I crashed every existing user of my QR scanner app with one bad Room migration — added a label field, bumped the schema version, shipped, and watched the launch graph die. Below is everything I do now to avoid that, plus the entity/DAO/ViewModel patterns that turn Room from another framework chore into the fastest way to ship structured data on Android.

I shipped my first QR scanner app without scan history. Users complained. Fair enough - scanning the same WiFi QR code every time is annoying. So I added history using raw SQLite.

That was a mistake.

Cursor management, forgetting to close database connections, SQL typos that only crashed in production. I spent more time debugging database code than building actual features. When I rewrote it with Room, the scan history feature took an afternoon instead of a week.

Raw SQLite vs Room

Here's what fetching scan history looked like before Room:

fun getAllScans (): List < ScanRecord > { val scans = mutableListOf < ScanRecord >() val db = dbHelper .…